My vote, at least up until now, has been the Diehard. I haggle with the service dept and usually get a few dollars off and their warranty is longer than most. (I did put an Interstate battery in my coupe because the local Sears store closed.
......recently, for what its worth, Consumer Reports tested batteries, and told how they do it, and surprisingly Wal-Mart came out on top.
Problem is, what is good today cannot be counted on tomorrow. The bean counters are always looking for away to cut a few pennies of cost off of the millions or batteries, thus profiting thousands of dollars. The best advice is shop around and be informed. before laying out our hard earned dollars.